1. Field of the Invention
Apparatuses consistent with the present invention relate to a multi-view autostereoscopic display apparatus and, more particularly, to a multi-view autostereoscopic display apparatus with improved resolution.
2. Description of the Related Art
Autostereoscopic display apparatuses produce a left eye image and a right eye image having a binocular parallax and separately direct the left and right eye images to a left eye and a right eye, respectively. The user recognizes the left eye image and the right eye image provided by the autostereoscopic display apparatuses through the retinas of the corresponding eyes and thus can see a stereoscopic image. In general, autostereoscopic display apparatuses can be roughly classified into a parallax barrier type and a lenticular type.
FIG. 1 shows schematically a related art parallax barrier type autostereoscopic display apparatus 10 including a backlight unit 11, a display panel 12, and a parallax barrier 14. First and second images are displayed on alternating vertical pixels 13 of the display panel 12 and separated by the parallax barrier 14 having vertical narrow slits such that a viewer's left and right eyes respectively see the first and second images. That is, the first and second images displayed on the display panel 12 are separately directed by the parallax barrier 14 toward different viewing zones 15a and 15b. When the two eyes are located in different viewing zones 15a and 15b, the first and second images having binocular parallax are distributed to the left and right eyes such that the two eyes receive the images of different view points to see a stereoscopic image.
A lenticular type autostereoscopic display apparatus using a lenticular lens sheet composed of vertical microlenses produces a stereoscopic image based on the same principle as that of the parallax barrier type autostereoscopic display apparatus of FIG. 1. A stereoscopic image, displayed with the related art parallax barrier type autostereoscopic display apparatus of FIG. 1 or the related art lenticular type autostereoscopic display apparatus, can be seen by several viewers simultaneously. However, the related art autostereoscopic display apparatuses have a problem in that the horizontal resolution of the stereoscopic image appears two times less than the original panel resolution. The related art autostereoscopic display apparatuses have another problem in that the viewer's head needs to be kept horizontally within a narrow zone of about ±3 cm to see a correct stereoscopic image. For example, the viewer's left eye should be located in a second viewing zone 15b and the viewer's right eye should be located in a first viewing zone 15a in FIG. 1. If the left eye is located in a first viewing zone 15a and the right eye is located in a second viewing zone 15b due to his or her slight movement, he or she sees the images in reversed perspective.
FIG. 2 shows schematically a related art 4-view autostereoscopic display apparatus 20 with an improved degree of freedom. Referring to FIG. 2, the multi-view autostereoscopic display apparatus 20 includes a backlight unit 21, a display panel 22, and a parallax barrier 24. While the autostereoscopic display apparatus 10 of FIG. 1 is configured such that each slit of the parallax barrier 14 covers two pixels 13, the multi-view autostereoscopic display apparatus 20 of FIG. 2 is configured such that each slit of the parallax barrier 24 covers four pixels 23. Also, the pixels 23 of the display panel 22 alternately and vertically display first through fourth images of slightly different view points, unlike the pixels 13 of the display panel 12.
Then, referring to FIG. 2, four viewing zones 25a through 25d are repetitively formed in a horizontal direction at a viewing distance in front of the display panel 23. In this case, the viewer's left and right eyes may be respectively located in third and fourth viewing zones 15c and 15d, second and third viewing zones 15b and 15c, or first and second viewing zones 15a and 15c. Accordingly, as the viewer moves from side to side, he or she may see images with slightly changed view points. However, if the viewer's left and right eyes are respectively located in the fourth and first viewing zones 15d and 15a, he or she sees the images in reversed perspective. Such discontinuity features can be solved by increasing the number of view points. However, the greater is the number of view points, the lower is the horizontal resolution. For example, in the 4-view autostereoscopic display apparatus of FIG. 2, horizontal resolution is 4 times lower than the original resolution. In an 8-view autostereoscopic display apparatus, horizontal resolution is 8 times lower than the original resolution.